Quick, reliable, and cost effective analytical and diagnostic devices for instance devices for use in point of care are desirable.
In many assays, detection conjugate and possibly further reagents are predispensed or integrated in the device, setting aside the need for separate addition of reagents by the user.
A common type of disposable assay device comprises a zone for receiving the sample, a reaction zone, and optionally a transport or incubation zone connecting the receiving and reaction zone, respectively. These assay devices are known as immunochromatography assay devices or simply referred to as strip tests.
PCT/SE03/00919 relates to a micro fluidic system comprising a substrate and provided on said substrate there is at least one flow path comprising a plurality of micro posts protruding upwards from said substrate, the spacing between the micro posts being small enough to induce a capillary action in a liquid sample applied, so as to force said liquid to move.
PCT/SE2005/000429 shows a device and method for the separation of a component in a liquid sample prior to the detection of an analyte in said sample, wherein a sample is added to a receiving zone on a substrate, said substrate further optionally comprising a reaction zone, a transport or incubation zone connecting the receiving and reaction zone, respectively, forming a flow path on a substrate, wherein said substrate is a non-porous substrate, and at least part of said flow path consists of areas of projections substantially vertical to the surface of said substrate, and having a height, diameter and reciprocal spacing such, that lateral capillary flow of said liquid sample in said zone is achieved, and where means for separation are provided adjacent to the zone for receiving the sample.
PCT/SE2005/000787 concerns a device for handling liquid samples, comprising a flow path with at least one zone for receiving the sample, and a transport or incubation zone, said zones connected by or comprising a zone having projections substantially vertical to its surface, said device provided with a sink with a capacity of receiving said liquid sample, said sink comprising a zone having projections substantially vertical to its surface, and said sink being adapted to respond to an external influence regulating its capacity to receive said liquid sample.
PCT/SE2006/000745 relates to an absorbing zone for establishing and/or maintaining fluid transport through or along said at least one fluid passage is manufactured on the basis of a non-porous substrate, having projections substantially perpendicular to said surface, and said projections having a height, diameter and a distance or distances between the projections such, that lateral capillary flow of said fluid in said zone is achieved.
Although the assay devices comprising projections according to the prior art are working satisfactory there is still room for a further improvement regarding for instance the control of the dissolution of a substance that is applied on the device.